Steering stem ring nut(how do you torque it)


8 replies to this topic
  • CaptainKnobby

Posted 24 March 2007 - 01:42 PM

#1

:applause: Repacked the steering stem bearings in my 06 yz450f today and was wondering how the heck do you torque the ring nut? The manual says to torque it to 38 ft. pounds (53nm) and then back off 1 turn then torque to 5 foot pounds........ Will a socket fit the ring nut and if so what size? It would have to be a deep well socket because it would have to go over the stem so far.

  • Mataz

Posted 24 March 2007 - 03:27 PM

#2

CaptainKnobby
I greased mine today also. When I reasembled the front end, I forgot to tighten the ring nut, then turn the bike to the stops to seat the bearings, loosen, then tighten it all down. My question is do I have to take out ALL of the play with the ring nut before I torque down on the nut on top of the triple clamps. The last time I did it, the top nut had effect on the play, so it was back and forth between tightening the ring nut, then the final top nut to get the play out and how loose you wanted the front end to be...ie flops from being straight with the front end down off the ground.

  • CaptainKnobby

Posted 24 March 2007 - 06:58 PM

#3

All Iam going to do is tighten the ring nut finger tight while holding it with a rag and then take a hammer and a punch and turn it about 12 milimeters more. Then put the top clamp on and screw the steering nut on and torque it down to 105 foot pounds and see what that does.

  • tnl

Posted 24 March 2007 - 10:19 PM

#4

Just turn the bars and feel the amount of torque and re tighten with a punch till it gets a little tight and back it off. Just be sure you tighten in small amounts about 1/8th a turn so you don't ruin the bearing asembly.

  • Butta

Posted 26 March 2007 - 06:30 AM

#5

Just turn the bars and feel the amount of torque and re tighten with a punch till it gets a little tight and back it off. Just be sure you tighten in small amounts about 1/8th a turn so you don't ruin the bearing asembly.



Also be sure you check that the bottom bearing is actually being "pressed" down on the steering stem as you tighten it. If the stem is still visible below the bearing, you need to tighten it some more.

  • Yamahafan

Posted 26 March 2007 - 06:48 AM

#6

All Iam going to do is tighten the ring nut finger tight while holding it with a rag and then take a hammer and a punch and turn it about 12 milimeters more. Then put the top clamp on and screw the steering nut on and torque it down to 105 foot pounds and see what that does.


This is very close to GrayRacer's approach which I have used with much success. After torqing the crown nut very tight with a punch or spanner wrench to seat the bearings, then relase the pressure, them tighten the crown nut as tight as you can with your hands and a rag (unless you arm wrestle for a living). I have a pretty good grip from playing ice hockey and I tighten the crown nut with a Mechanic's Grip glove as tight as possible and then go another quarter turn with a punch. Obviously this work is performed while the bike is on a stand with the wheel in the air. Check the steering play for appropriate looseness and go back and tighten more with the punch or spanner wrench as needed.

  • wrecking crew

Posted 26 March 2007 - 08:44 AM

#7

You can go to pitposse.com and they have a ring nut wrench that has a slot in it for the torque wrench to set in so that you can tighten it with that. The wrench is like 15 - 20 dollars. It works great. The wrench is also adjustable so that it fits any size ring nut.

  • N2Roost

Posted 26 March 2007 - 09:22 PM

#8

torque it to 38 ft. pounds (53nm) and then back off 1 turn then torque to 5 foot pounds........

The reason for this is to "set" the bearing and then bring it to the torque spec. This is required on all timken (taper) bearings.

BTW - I have a steely frame and set mine much tighter then 5 lbs. In this application (steering stem) the bearings can tollerate overtightining without ill effects. A small amount of "resistance" is beneficial and lessens chassis vibration. Years of experience have afforded me adjusting bearings without a torque wrench. Over time you'll learn a feel.

Caveat: it's possible the steerer torque is critical and sensitive on an AL frame. Anybody else on this??

  • grayracer513

Posted 27 March 2007 - 07:52 AM

#9

Caveat: it's possible the steerer torque is critical and sensitive on an AL frame. Anybody else on this??

I don't think it's any more critical on an aluminum frame. It's still an issue of the bearing getting the right pre-load. "Timken" (tapered roller) bearings require some pressure on them exclusive of the load they carry in order to work properly. It also keeps them from battering the races in an application like this that is subject to a lot of shock.

The reason this nut is tricky to set is that when you run the ring nut down, the pressure on the nut pushes it up against the bottom side of the threads on the steering stem. Then, when the crown nut is set down over it, that pressure forces the ring nut down against the top side of the stem threads. The bearings will then be tighter by the amount of the clearance in the threads in the nut. The very light 5 ft/lb torque on the ring nut reflects the expectation that the crown nut will tighten the bearing stack further.

The way to truly set up a pair of tapered roller bearings is to load them to a particular rotating torque. After assembly, the amount of torque required to keep the bearings rotating (not to start them turning) is measured with an in/lb torque wrench. The manual makes no reference to this method, so I would have to guess that it would be about 8-12 inch pounds with the crown nut torqued down, and no fork tubes installed.




 
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